The ancients, all philosophers and doctors in ancient China defined everything in the universe in terms of Yin and Yang. The original meaning stems simply from Yang – facing the sun and Yin – in the shade of the sun.
Yin and Yang can be divided according to properties:
| YANG | YIN | |
| Space | Upward, outward, left, south, . | Downward, inward, right, north, earth |
| Heaven | Earth | |
| Sun | Moon | |
| Time | Day, spring, summer | Night, autumn, winter |
| Temperature | warm, hot | Cool, cold |
| Moisture | Dry | Moist |
| State | Lucid | Turbid |
| Motion | Ascending | Descending |
| Movement, excitement | Stillness, inhibition |
There is not a fix barrier between where Yang ends and Yin starts, however within Yang, there are degrees of a more Yin-like Yang, for example: A cold evening at the beginning of spring is more Yin than a warm day in the middle of spring. Likewise, slow movement is more yang than stillness but , of course, faster movement is yang in comparison to that slow movement which here will be classified as yin.These subdivisions are infinite and it is all a question of relativity what is more or less Yin or Yang.
Yin and yang are not only contrary but also interdependent. Both opposites require each other to function. Solitary yang cannot exist and solitary yin cannot grow. The Chinese Medicine diagnosis is normally based on a definition such as yang excess, yin deficiency, blood deficiency. Patients with deficient yin will be supplemented with yang to generate yin creating more balance. Patients with a blood deficiency can be treated by supplementing qi to produce blood and similarly a qi deficiency will be treated by supplementing the blood to improve the qi.
Yin and Yang are normally in a state of waxing and waning creating a natural dynamic of yin waning/yang waxing and yin waxing/yang waning. This should occur within a certain range which if exceeded will cause a yin/yang imbalance.
If yin or yang wanes or waxes to an extreme, then yin will become yang, and yang will become yin. In terms of Chinese Medicine, this will be referred to as an excess of yin or yang. An example in nature would be: autumn, we have yin waxing and yang waning and at the winter solstice, yang will start waxing and yin will be waning.
As stated in The Book of Lao Zi
“Reversal is the movement of the Tao”- Lao Zi
In other words, the natural way. When the sun has reached its meridian, it declines and when the moon has become full, it wanes.
True both in nature and in human relations. Part of Chinese philosophy is to remain hopeful even in a time of failure and poverty and be cautious in a time of success and prosperity. Any philosophy that promotes either yin or yang alone arrives at alienation and a meaningless existence, lack of direction. Yin and yang are opposites and at the same time complementary to each other and maintained in an essential balance.
Similarly, there is no pure yin or pure yang, they penetrate each other. Each yin will contain some yang, and each yang will contain some yin. The two penetrate each other for meaningful survival and stability. In society, pure socialism without free enterprise is not feasible as is pure free enterprise with no aspect of socialism. – A glimpse of hope for gradual exit from unwelcome regimes….
We can conclude excessive yin becomes yang and excessive yang becomes yin. Just think of catching cold in very cold conditions, you may catch cold with the result: a fever – heat. A cold pathogen we are exposed to in winter may remain dormant and transform to heat in the spring. As it reemerges in spring in the form of “latent heat”we may have the same symptoms as if simply catching cold in winter.
“Yang accumulates and goes up, forming the heaven, Yin concentrates and goes down, forming the earth”
“Yin is calm and yang is active.”
“Yin deficiency causes interior heat and Yang excess causes exterior heat.”
“The over abundant Yin will damage Yang and the over abundant Yang will damage Yin.”
“The over abundant Yang will lead to a heat syndrome and the over abundant Yin will bring about a cold syndrome. The extreme heat may lead to cold, and the extreme cold lead to heat.”
The human body itself can be divided into yin and yang as follows:
| YANG | YIN |
| Upper body | Lower body |
| Exterior | Interior |
| Back | Chest and abdomen |
| Chest | Abdomen |
| Lateral side, outside of limbs | Medial, inside of limbs |
| Fu organs (transport and transform) | Zang organs (store essence) |
However, we should note the subdivisions, the heart and lungs located in the chest are more yang than the liver, spleen, kidney located in the abdomen. Each organ can have yin or yang properties, heart yang, heart yin, liver yang, liver yin etc. For example, qi, blood, body fluids are per se yin but their functions are yang (movement.)
Any philosophy which exists based on the sole existence of the strong, the positive, the light and visible and denial of the existence of the dark, the weak, the poor, the invisible and the spiritual is in alienation with nature. Any interaction or communication is impossible without the mechanisms of the yin-yang principle. Without these mechanisms, we can find ourselves in meaninglessness and alienation and once this alienation becomes out of proportion, it threatens the survival of human society.
Yin and Yang exist for the balance in nature: between the sun and the moon, between the earth and the heavens; the beginning with the yang and the continuation with the yin. The prime example is interaction between male and female which ensures production and our survival. All phenomena are created from the existence of these opposite yet interacting elements.
This pair of opposites together with the group of the five elements forms the basis of Chinese Medicine as presented by the Chinese philosopher, Hsun Tzi. The interdependency between the opposing elements yin and yang is essential for the survival of any living system. However without this complementarity there will be no genetic replication in any part of nature. Examples of the complementarity of yin and yang appear in materialism and idealism, the biological and the spiritual and no one side having moral priority over the other. The natural rise and fall of the seasons and nature and our interaction with them proves all things are related and the will to survive is our raison d’être.
It is also worth noting that harmony is not static but in a constant state of change and realignment. It exists in cycles and a dynamic homeostasis ensures survival. Its dynamic movement however will lead us in the long run to an ever increasing level of morality, stability of society and a maturation of the civilisation. There will still be cycles and a dynamic homeostasis but within preferable parameters of a civilisation with improved values and interaction.
Diseases and excesses are regarded as alienation in the yin and yang theory, and must be removed to re establish a balanced yin and yang in the living organism. When symptoms have reached an extreme this will bring about a reversal in the form of a defence mechanism, restoring a yin yang balance through the five element system.
According to the Zang-fu organ classification, we know which organs are Yin and which Yang. The interdependency between the organ pairs is proof of the interdependency between Yin and Yang.
The Yin organs are solid, those most vital to the body. Heart, Spleen, Lung, Kidney, Liver, Pericardium are all Zang organs.
The Yang and Fu organs being the remaining: Small Intestine, Stomach, Large Intestine, Bladder, Gall bladder, Triple Heater.
The Zang organs provide us with life, Qi and Blood.
The Fu organs are considered to be empty however they are able to receive and process.
The Zang spleen and the Fu stomach are relevant to the middle energiser, governing digestion and absorption of food as a source of Qi, blood and body fluids. The spleen governs transportation and transformation and the stomach reception and digestion. The stomach receives food, digests it which is then transported and transformed to the spleen where it is also digested, nutrients are absorbed and the stomach receives. Normal digestion and absorption of food is guaranteed by this cooperation between stomach and spleen.
Spleen qi raises the lucid nutrients to the heart and lung and the stomach qi descends the turbid downwards as waste. If descent of the turbid by the stomach qi does not function efficiently, the spleen will also not be able to raise the lucid. Consequently a mixture of the lucid and turbid will accumulate in the middle abdomen.
Only the coordination between ascent of spleen qi and descent of stomach qi ensures the digestion process.
“Ascent ensures normal functioning of the spleen and Descent normal functioning of the stomach”.
The spleen, zang and yin in nature, prefers dryness and dislikes dampness whereas the stomach, fu and yang in nature, likes moisture and dislikes dryness. Dampness is yin in nature thus not welcomed by the spleen and dryness is yang in nature so pushed away by the stomach. Physiologically, dryness of the yang qi in the stomach is helpful to the spleen to transform and raise nutrients to the heart and lungs. However the yin fluid in the spleen is excellent for the stomach to descend waste.
As we see, the stomach and spleen cooperate together as partners. When we check the five elements relation to the organs, we can identify other Zang Fu “cooperating partner organs.”
The Zang lung transmits fluid down to the Fu large intestine ensuring smoothness of Large Intestine Qi and also cleansing of the lung with a descent of lung Qi. The two organs cooperate and any blockage of the cleansing and transmission of qi would cause a cough or constipation.
The Zang kidney and the Fu bladder are interdependent in their function to excrete urine. The kidney Qi transforms excess water in the body to urine and transports it to the bladder to be discharged from the body.
This relationship is more complex as together with the kidney the triple heater comes into play. The kidney governs water and the triple heater is the water passage.The triple heater can transport water from the whole body to the kidney provided the kidney Qi is functioning correctly. Any interruption to this process such as damp heat in the bladder may cause over frequent or painful urination. If the problem lies with the kidney Qi, it will lead to an accumulation of water in the triple heater and may eventually cause oedema.
The Zang liver and the Fu gallbladder both govern dredging and dispersing. The liver secretes and excretes bile while the gallbladder excretes and stores bile, the gallbladder being located beside the liver. If the liver fails to dredge and disperse effectively, this will cause interrupted flow of the gallbladder Qi resulting in liver Qi stagnation. Should both the liver and gallbladder not perform their functions of dredging and dispersing, this may cause hypochondriac pain which is pain emitted from the liver-gallbladder area. Anorexia or jaundice could result in extreme cases.
The Zang heart and the Fu small intestine are dependent on each other, the heart governs blood vessels. The small intestine receives chyme – that semi-digested food which has been chewed in the mouth, – passed through the oesophagus and absorbed digestive secretions from the stomach before entering the small intestine – the small intestine absorbs food nutrients and turns them into blood to enrich the heart. If the heart shifts heat to the small intestine, this can lead to a red tongue, sores in the mouth, agitation (dysphoria), anxiety, a very low output of brownish, painful urine (oliguria).
The interdependency and interaction between Zang and Fu organs which enable an efficient and harmonious functioning of our body is further proof of the essential Yin Yang interrelation for our existence.